Currently, there is a growing market for acoustical wall systems. Sounds of urban living can penetrate homes and offices, making it difficult to find quiet interior spaces. Noise pollution is an increasing problem and solutions are being sought that both reduce noise and produce an aesthetically pleasing appearance.
Acoustical ceiling panels have been used for some time, but have not been accepted as providing an aesthetically pleasing appearance. The panels are often formed of a mineral wool composition that is very absorbent of sound. Finishing of the panels includes embossing or needling the panel surface, creating openings into which sounds enter. From the openings, a large fraction of the sound waves are absorbed by the mineral wool. While these acoustical panels are popular for use in basement rooms and recreational areas, they are seldom used in main living areas as they are not considered to be as aesthetically pleasing as other finishing options.
Conventional plaster or dry wall systems are frequently used in the main living areas of homes and office areas. This medium is inexpensive, produces a smooth, monolithic surface and readily receives a number of decorative finishes, such as paint, stencils, wallpaper, decals and the like. However, dry wall and plaster absorb little sound, reflecting some of the sound back into the living area. Some sounds are also distorted, adding to the noise pollution problem. Moreover, there is little variability in the sound attenuation, particularly after the system has been installed.
Even in situations where one of these options provides an ideal sound absorbency solution for a particular room for a time, things change. The use for the room may change to one having different sound absorbency requirements. A TV room might be converted to a study or office. Elements within the room can be replaced with other elements having different sound absorbency, such as replacing wooden furniture with upholstered furniture or carpeted floors with hardwood flooring. More noise may be entering from outside the room. These and other circumstances provide instances where it is desirable to change the acoustical characteristics of the acoustical system even after the sound system has been put into place.
One method of changing the acoustical properties is to totally remove the current acoustical system and replace it with one matching the new desired acoustical properties of the space. Although this method produces the desired acoustical properties, it is extremely expensive and time consuming to replace plaster, wallboard or other acoustical panels with another wall system.
Coatings have been applied to wall system with various degrees of success. The addition of paint or wallpaper to a wall system usually decreases sound attenuation by covering up or sealing pores that allow penetration of sound into the interior of the wall system where it can be absorbed. An additional coating on top of the paint or wallpaper would not significantly increase the sound absorbency of the wall system. Even the sounds that penetrated the entire thickness of the second coating would be reflected by the first coating. Those sounds would again travel the thickness of the second coating and out into the occupiable space. Only sounds that were absorbed by the second coating would be attenuated.
Another known coated panel is an acoustical ceiling tile to which an acoustically transparent coating is applied during installation. The coating gives the smooth, monolithic appearance of wallboard but allows sound to penetrate into the panel. Once installed, the sound deadening properties of this system are not changed without removal of the whole system and reinstalling a new system.
There is an ongoing need for an acoustical system for indoor spaces that will accommodate dynamics that require different levels of sound attenuation without requiring reconstruction of the acoustical walls and or ceilings of the space.